Because my hometown Weifang is the hometown of vegetables, locally produced tomatoes can be exported to all parts of the country, and I am very familiar with tomato seedling raising technology. The following methods are generally adopted to prevent the overgrowth of seedlings. Let's introduce it below.
First of all, let's talk about what it is and how it is expressed.
First, the external characteristics and causes of tomato overgrowth seedlings The so-called overgrowth seedlings refer to tomato seedlings with thin and long stems, large spacing between stems, thin leaves, light green leaves, tender but not old. There are few roots underground.
What causes tomato seedlings to grow white?
There are many reasons for the white growth of tomato seedlings, including:
1, insufficient light and high temperature at seedling stage, especially at night.
2. Too much nitrogen fertilizer and water.
3. Sowing is too dense and the seedlings are crowded.
4. Transplanting is not timely.
There may be white growth in the process of tomato seedling raising, but the reasons for white growth are different in each period. The most likely period of excessive growth and serious yield reduction is from tomato emergence to cotyledon development. At this time, the overgrowth is mainly due to the high sowing density and the failure to clear the plastic film in time after emergence, which leads to overgrowth of seedlings. If the temperature is not lowered in time after emergence, it is easy to cause excessive elongation of seedling stems, leading to virtual length.
So what measures should be taken to prevent excessive growth of tomato seedlings?
Two or five methods can prevent excessive growth of tomato seedlings. The first method is cutting and planting in time.
After the tomato seedlings are unearthed, they should be interplanted in time to prevent the seedlings from growing white due to crowding. At the same time, when nearly one third of the seedlings are unearthed, the plastic film should be removed in time. Seedlings should be spaced 2-3 times. If possible, transplanting should be carried out when the seedlings have 2 leaves with 1 heart.
The second method is to strengthen ventilation and transparency and control temperature and humidity.
Ventilation and light transmission should be carried out after the tomato seedlings are unearthed, before entering the heel, after delaying the seedlings in the heel and before planting, so as to reduce the temperature and humidity of the seedbed, strengthen low-temperature exercise and control the excessive growth of the seedlings.
The third method is reasonable fertilizer and water management.
Whether it is the management of fertilizer and water in seedbed or the preparation of nutrient soil, we should pay attention to the application of phosphorus and potassium fertilizer, and do not apply too much nitrogen fertilizer. At the same time, it is necessary to control the watering and fertilization of the seedbed. If fertilizer can be sprayed on the leaves, it should not be topdressing, and nitrogen fertilizer should not be applied too much.
The fourth method is to adjust the seedling spacing in time.
If seedlings are raised in nutrient pots, or is is followed in nutrient pots, about 20 days before planting nitrogen eggplant seedlings, if the distance between nutrient pots is too close, seedlings can be appropriately moved to separate large and small seedlings and expand the distance between seedlings.
Fifth, drugs control void growth.
If weeds are found in tomato seedlings, in addition to the above four methods, Bordeaux mixture, chlormequat chloride or other growth control agents can be used to control weeds.
In a word, tomato seedling overgrowth is a common problem for many reasons. Continuous rainy weather, high humidity of soil and air in seedbed, excessive amount of nitrogen fertilizer in nutrient soil, untimely ventilation and lighting in management, overcrowding of seedlings, etc. Will cause tomato seedlings to grow in vain, so it is necessary to distinguish the reasons and deal with them according to different reasons.